This invention relates to irrigation systems, and more particularly, to an irrigation system including an irrigiation line supported by wheels which may be turned perpendicular to the line, and parallel thereto as selected.
In the use of a wheel-supported irrigation line, with the wheels being normally positioned perpendicular to the line to drive the line in a direction perpendicular to its length, it is often found desirable to provide that the wheels may be selectively turned so as to be parallel to the length of the line. With the wheels so positioned, the line may then be towed from one location to another, i.e., towed endwise, so as to be movable in a relatively convenient manner. U.S. Pat. No. 3,583,639 (assigned to the assignee of this invention) discloses a system wherein the wheels can indeed be so selectively positioned. While such a system has proved highly effective in operation, it will be seen that in the disconnecting of the drive from the wheels, a gear is slidably moved along a shaft by a linkage and fork structure. It will be understood that it is always desirable to increase efficiency of operation of an apparatus, meanwhile maintaining high efficiency of use.
U.S. Pat. Nos. 3,623,662 and 3,512,548 also disclose systems generally similar to the above-described type, wherein the wheels thereof may be pivoted from one position to another. However, it will be seen that in each patent each wheel must be pivoted by a relatively complicated arrangement independent of the pivoting of any other wheel.